[src/trunk]: src/sys/arch/mac68k/obio Raise spl4 to spl6 in quick_go--I am no...

[briggs <briggs%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/386af8534fc8
branches:  trunk
changeset: 473394:386af8534fc8
user:      briggs <briggs%NetBSD.org@localhost>
date:      Tue Jun 01 03:40:12 1999 +0000

description:
Raise spl4 to spl6 in quick_go--I am now experimenting with interrupts
at levels 5 (sound) and 6 (via1) on the Q700.
Raise splhigh when reading and writing registers.  It's ugly, but it's
possible that we could get an interrupt from a higher-level source,
causing a re-read of a memory location.
This is not good when, e.g., we are reading the interrupt register.
Ideally, we would just raise splhigh() in ncr53c9x_readregs(), but
that's m.i. code, and it may be expensive on other architectures.

diffstat:

 sys/arch/mac68k/obio/esp.c |  29 ++++++++++++++++++++---------
 1 files changed, 20 insertions(+), 9 deletions(-)

diffs (96 lines):

diff -r 756b6e8abe20 -r 386af8534fc8 sys/arch/mac68k/obio/esp.c
--- a/sys/arch/mac68k/obio/esp.c        Tue Jun 01 03:37:02 1999 +0000
+++ b/sys/arch/mac68k/obio/esp.c        Tue Jun 01 03:40:12 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: esp.c,v 1.20 1998/12/22 08:47:07 scottr Exp $  */
+/*     $NetBSD: esp.c,v 1.21 1999/06/01 03:40:12 briggs Exp $  */
 
 /*
  * Copyright (c) 1997 Jason R. Thorpe.
@@ -334,8 +334,13 @@
        int reg;
 {
        struct esp_softc *esc = (struct esp_softc *)sc;
+       u_char  v;
+       int     s;
 
-       return esc->sc_reg[reg * 16];
+       s = splhigh();
+       v = esc->sc_reg[reg * 16];
+       splx(s);
+       return v;
 }
 
 void
@@ -345,12 +350,15 @@
        u_char val;
 {
        struct esp_softc *esc = (struct esp_softc *)sc;
-       u_char v = val;
+       u_char  v = val;
+       int     s;
 
        if (reg == NCR_CMD && v == (NCRCMD_TRANS|NCRCMD_DMA)) {
                v = NCRCMD_TRANS;
        }
+       s = splhigh();
        esc->sc_reg[reg * 16] = v;
+       splx(s);
 }
 
 void
@@ -502,9 +510,12 @@
        u_char val;
 {
        struct esp_softc *esc = (struct esp_softc *)sc;
-       u_char v = val;
+       u_char  v = val;
+       int     s;
 
+       s = splhigh();
        esc->sc_reg[reg * 16] = v;
+       splx(s);
 }
 
 int
@@ -606,7 +617,7 @@
 static int espspl=-1;
 #define __splx(s) __asm __volatile ("movew %0,sr" : : "di" (s));
 #define __spl2()  __splx(PSL_S|PSL_IPL2)
-#define __spl4()  __splx(PSL_S|PSL_IPL4)
+#define __spl6()  __splx(PSL_S|PSL_IPL6)
 
 void
 esp_quick_dma_go(sc)
@@ -653,7 +664,7 @@
        if (esc->sc_datain == 0) {
                while (esc->sc_pdmalen) {
                        WAIT;
-                       __spl4(); *pdma = *(esc->sc_pdmaddr)++; __spl2()
+                       __spl6(); *pdma = *(esc->sc_pdmaddr)++; __spl2()
                        esc->sc_pdmalen -= 2;
                }
                if (esc->sc_pad) {
@@ -662,19 +673,19 @@
                        c = (unsigned char *) esc->sc_pdmaddr;
                        us = *c;
                        WAIT;
-                       __spl4(); *pdma = us; __spl2()
+                       __spl6(); *pdma = us; __spl2()
                }
        } else {
                while (esc->sc_pdmalen) {
                        WAIT;
-                       __spl4(); *(esc->sc_pdmaddr)++ = *pdma; __spl2()
+                       __spl6(); *(esc->sc_pdmaddr)++ = *pdma; __spl2()
                        esc->sc_pdmalen -= 2;
                }
                if (esc->sc_pad) {
                        unsigned short  us;
                        unsigned char   *c;
                        WAIT;
-                       __spl4(); us = *pdma; __spl2()
+                       __spl6(); us = *pdma; __spl2()
                        c = (unsigned char *) esc->sc_pdmaddr;
                        *c = us & 0xff;
                }